using Implab; namespace Implab.Automaton.RegularExpressions { public abstract class BinaryToken : Token { readonly Token m_left; readonly Token m_right; public Token Left { get { return m_left; } } public Token Right { get { return m_right; } } protected BinaryToken(Token left, Token right) { Safe.ArgumentNotNull(m_left = left, "left"); Safe.ArgumentNotNull(m_right = right, "right"); } } }